Tire pressure indicator



c. CQAKIN TIRE PRESSURE INDICATOR July 11, 1944.

3 Sheets-Sheet 1 Filed Jan. 2, 1942 July11,1944. AKIN 2,353,428

TIRE PRESSURE INDICATOR Filed Jan. 2. 1942 3 Sheets-Sheet 2 July 11, 1944. c. c. AKIN TIRE PRESSURE INDICATOR Filed Jan. 2, 1942 3 Sheets-Sheet 3 Patented July 11, 1944 TIRE PRESSURE INDICATOR Clarence C. Akin, Seminole, Okla, assignor to J. D. Akin, Seminole, Okla.

Application January 2, 1942, Serial No. 425,483

3 Claims.

This invention relates to a device adapted to be associated with the wheels, carrying pneumatic tires, of a vehicle foractuating pressure gages located on the dash or instrument board for in.- dicating the air pressure in the tires of a motor vehicle, aeroplane or other carrier equipped with pneumatic tires.

More particularly, it is an aim of the invention to provide for actuating an indicator device, which can be readily mounted in a vehicle wheel and in the brake drum associated therewith, which will not interfere with removing or applying the wheel.

More particularly, it is an aim of the invention to provide a pressure indicating device including an annular chamber disposed within a vehicle wheel and in communication with the inflated inner tube thereof, and which is provided with a plunger adapted to be actuated by the air pressure in the tube and against the action of spring means, for actuating the air gage operator.

Still a further aim of the invention is to provide'a rotatable ring having studs for engaging againstthe air pressure actuated plunger, and which is rotatable with the wheel and arranged to be engaged by a plurality of rollers mounted on spring pressed rods, which are adapted to be slidably mounted on the brake drum, and to one of which an air pressure gage operator is connected.

Still a further aim of the invention is to provide an air pressure indicating device for vehicle wheels which is adapted to function when the wheel is mounted as a spare.

Other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, which illustrate a preferredembodiment thereof, and

wherein- 1 Figure l is, a side elevational view looking toward the outer'side of a motor vehicle wheel provided with a pneumatic tire,

Figure 2 is an enlarged horizontal sectional view taken substantially along the plane of the line 2-2 of Figure Figures 3, 4 and are sectional views of portions of the wheel and of the brake drum asso ciated therewith, taken substantially along the planes indicated by the lines 3-3, 44 and 5--5, respectively, of Figure 2,

Figure 6 is a fragmentary horizontal sectional view, partly in plan, showing the wheel mounted on a spare tire rack, and

Figure 7 is a sectionalview of a portion of the wheel taken substantially along the plane indicated by the line |'l of Figure 3.

Referring more particularly to the drawings, wherein like reference characters designate like or corresponding parts throughout the different views, [0 designates generally a wheel on which is mounted a pneumatic tire casing I l containing an inner tube l2. The rim l3 of the wheel I0 is provided with anopening 14 through which a valve stem [5 extends. The valve stem I5 is of conventional construction and is adapted to contain a conventional valve, not shown.

The wheel I0 is provided around the hub thereof with an annular chamber 16 which opens at I I through the inner side of the wheel and which contains an annular plunger 1-8 which is mounted to slide toward and away from the open inner side of the chamber 16 and the closed outer side thereof. The annular plunger I8 is provided with yieldable sealing members I9 which bear against the inner sides of the inner and outer annular walls of the chamber It to prevent leakage past the plunger l8, for a purpose which will hereinafter becom apparent. A plurality of contracile coil springs 20 are each anchored at one end thereof to the outer closed side of the chamber 15 and are disposed therein and are connected at their opposite ends to circumferentially spaced portions of the plunger [8 for urging the plunger toward the closed end of the chamber It. A flexibl hose or conduit 2| has one end thereof opening into the annular chamber I6, between its closed end and the plunger 18. The opposite end of the conduit 2] is detachably connected to the valve stem I5 and is adapted to contain conventional means, not shown, for depressing the valve thereof to per mit the air from the inner tube I2 to pass into the chamber I6 so that the pressure in the chamber equals the pressure in the inner tube. It will be readily obvious that the last mentioned end of the conduit 2| can be readily detached from the valve stem I5 to permit inflation of the inner tube l2. Furthermore, the conduit if applied, as seen in Figure 2, said conduit and the chamber Iii will combine to prevent deflation of the inner tube due to a leak valve. The wheel H3 is detachably mounted on the front plate 22 of the brake drum, in a conventional manner, by means of threaded stud and nut fastenings 23 which are disposed in an annular chamber 24 of the wheel hub which is disposed on the outer side of the annular air chamber [6.

A ring 25 is rotatably mounted in the brake drum and around the axle 26 of the Wheel Hi. As seen in Figure 2, the ring 25 is relatively wide radially and is preferably provided with two studs 21 which extend from the outer side thereof through openings 28 in the front plat 22 of the brake drum. The studs 2'! are provided with enlarged heads 29 at their free ends which are disposed to bear against the outer, exposed side of The back or dust guard plate 3i, relative which the wheel Ill and plate 22 are rotatably mounted, is provided with flanged openings in each of which is slidably mounted a rod- The flanged openings 32 are preferably disposed in diametrically opposed relationship to one another and substantially in a horizontal plane relatively to one another. -A housing 3t is provided with a flanged open end 35 which is secured. by L s tenings to the outer side of the plate 3! and registry with one of the flanged openings for receiving the outer end of one of the rods "The housing 35 is provided with a flanged open end 35 which is similarly attached to the outer side of the plate 3! to register with the other opening 32 for receiving the outer end of the other rod 33; The housing 35 is provided with a restricted opening 3! in its/opposite end and around which is disposed a nipple or annular flange 3B in which is secured one end of a flexible conduit 39. A flexible shaft ll! extends through the conduit 39 and has one end thereof extend ing through the opening 3! and fastened to the end of the rod 33 which is disposed in the housing 35. The opposite end of the flexible shaft il is adapted to be connected to a conventional air pressure gage, not shown, which may be of any suitable construction capable of being actuated by the reciprocating movement of the shaft and whichis adapted to be mounted on the dashboard or instrument board, not shown, of a vehicle on which the wheel ill is mounted.

The ends of the rods 33 which are disposed in the housings 34 36 each have 4! ex tending therothrough against which bears an expansion coil spring 42. The springs 42 are disposed in each of the housings 3d and and said springs have their opposite ends bear ng against the outer ends of said housings for urging the slidably mounted rods 33 inwardly of the brake drum and toward the ring 25. The 3-3 are provided with yoke shaped opposite ends through which extend pins 4%, on each of which is journaled an elongated roller The rollers 55 are disposed radially of the ring 25 and are adapted to frictionally engage the opposite side thereof and to roll thereon when the wheel 59 is rotating.

From the foregoing it will be obvious that the pressure of the air in each inner tube 52 of each of the wheels of a motor vehicle, not shown, will equal the pressure of the air in the annular chamber it, of the wheel it on which said inner tube i2 is mounted. This pressure will project the plunger 8 of the sa d chamber is against the action of the contractile springs 25 thereof for retracting the rods'33. The rod 3-3 which is connected to the gage actuating member will project said member, when said rod is retracted. As the pressure in the inner tube i2 diminishes the pressure in the chamber it, connected thereto, will likewise diminish allowing the springs 26 to retract the plunger [8 thus permitting the springs 42 to project the rods 33 so that the rod 33, which is connected to the member 49, will operate to retract said member 48. It will thus be readily apparent that when each wheel of a vehicle is provided with a pressure responsive ole-- vice, as shown in Figure 2, and when each of the members to is connected to a suitable gage, mounted on the dashboard of the vehicle, not shown the operator of the vehicle can ascertain at a glance the pressure in the tires of each of the wheels. The rod 33, which is not connected to the member is, and the parts associated therewith are provided so that an equal pressure or force will be exerted against the diametrically opposed points of the ring 25 to hold the ring substantially parallel to the plane of the wheel i The pressure exerted by the springs 52 is only suflicient to retain the rollers in engagement with the ring 25 andthe studs 21 in engagement with plunger 18 as springs 29 resist the air pressure in chamber [5. Openings 23 are provided with bushings 23a for slidably engaging studs 22 to prevent any rocking movement of the studs so that ring 25 will be supported thereby substantially parallel to the plate 22 and out of engagement with the axle. Studs 2'! can be secured to the ring 25 as by welding or by a threaded connection which will not mar the side of the ring, engaged by rollers 45, and the head 2% may be omitted or be formed after studs T! are in engagement with bushings 28a. The rollers 35 will roll on the ring 25 so as to hold the headed ends 29 of the studs 27 against the exposed side i of the plunger E8 to cause the ring 25 to move toward the plate 22 when the air pressure in the closed side of the chamber 15 diminishes.

It will be readily apparent that the wheel it can be mounted or demounted in a conventional manner.

Referring to Figure 6, 25 designates gencraliy a spare tire support including a supporting arm All and a plate or bracket 48 having studs 23' by which the wheel [B can be detachably mounted on the support :35. The plate 53 has diametri cally opposed openings in which rods 33 are slidably mounted. The outer end of one of the rods 33' is mounted in the housing corresponding to the housing 34, and the outer end of the other rod 33' is mounted in the housing 35', corresponding to the housing 35. The housings 3d and 36 are attached to the back side of the plate 48 and contain expansion coil springs 62' which bear against pins 4!, which extend through the rods 33' for urging said rods ou wardly of the housings 34' and 3B. A flexible conduit 39 is connected at one end to the flanged end 38' of the housing 36' and contains a flexible shaft it which is connected at one end thereof to the rod 33 of the housing 3E, and which is connected at its opposite end to an air pressure gage on the dashboard of the vehicle. As there is no movement of the wheel If! on the support the ring 25 and rollers G5 can be dispensed with. The outer ends of the rods 33' are therefore preferably provided with heads Q9 which extend into the open ide ll of the chamber It and which bear against the exposed side of the plunger 53. It will thus be readily apparent that the device is readily adapted for use for indicating the air pressure in a spare tire as well as the tires of the wheels which are in use.

Various modifications and changes are contemplated and may obviously be resorted to, provided they fall within the spirit and scope of the invention as hereinafter defined by the appended claims, as only a preferred embodiment of the invention has been disclosed.

I claim as my invention:

1. A tire pressure indicator comprising a vehicle wheel, a, pneumatic tire thereon, an annular chamber mounted on said vehicle wheel and opening inwardly thereof, conduit means connected to the chamber and to the pneumatic tire and forming a passage between the chamber and the tire, an annular plunger slidably mounted in said chamber and adapted to be moved inwardly of the wheel by the air pressure in the chamber, means for yieldably urging the plunger in the opposite direction, a brake drum on the wheel having front and back plates, a ring concentric with the rotatable axis of the wheel mounted in said brake drum, from which the wheel is detachable, means extending from said ring at a plurality of points through said front plate for sliding movement with the plunger, spring pressed rods slidably mounted in said back plate urged toward said ring, and said rods having portions engaging the ring, and a gage-actuating element connected to and actuated by one of said rods.

2. An air pressure indicating device as in claim 1, comprising a plurality of circumferentially spaced stop members disposed at the inner, open end of said annular chamber for restricting the movement of the plunger toward the open end of the chamber.

3. A tire-pressure indicator comprising in combination with a vehicle wheel and a pneumatic tire thereon, an annular chamber mounted on said wheel, concentric with the rotatable axis thereof, a conduit for connecting said chamber to the pneumatic tire, a plunger slidably mounted in said chamber adapted to be moved in one direction by the air pressure therein, spring means for moving said plunger in the opposite direction, a brake drum on said Wheel having front and back plates, a ring concentric with the rotatable axis of the wheel disposed in the brake drum, means extending from said ring through said front plate and engaging said plunger for sliding the ring toward and away from the inner side of the wheel following the movements of the plunger, a spring pressed rod slidably mounted in the back plate of the brake drum, said rod having one end engaging the ring and a gauge actuating element connected to the opposite end of the rod for actuation thereby.

CLARENCE C. AKIN. 

